A 52 yo male with severe mental illness overdosed on trazodone, DEET, and an old arsenic-containing pesticide found in his garage. The ED initially was not concerned about the pesticide, since the product was >40 yrs old, and therefore was felt to be non-toxic.
Patient presented with severe watery vomiting and diarrhea, but no blood was seen. VS were stable with only slight tachycardia, which responded to fluid replacement. EKG showed no abnormalities, no QTc prolongation. Vomiting had resolved once Poison Center was called for treatment advice.
Medical Toxicology consult through the Poison Center recommended obtaining a stat whole blood As and urine arsenic, then to start immediate chelation with DMSA due to signs and symp- toms consistent with acute inorganic As poisoning. The patient was immediately started on DMSA 10 mg/kg q 8 hr (30 mg/kg/d) for 5 days, then 10 mg/kg q 12 hr (20 mg/kg/d) pending lab test results.
The initial stat whole blood Arsenic was 186 μg/L (nl = 2–23), and spot urine Arsenic was 1,936 mcg/L (nl < 50 mcg/L), all inorganic arsenic. Continued DMSA chelation was recommended until urine and whole blood arsenic were normal. The following lab results were obtained while chelation was
ongoing:
Repeat whole blood arsenic on day 5 was 54 μg/dL (nl = 2–23)
24 hr Urine arsenic from day 9 was 131 μg/dL (nl < 50 mcg/l)
24 hr Urine arsenic on day 14 was 112 μg/L (nl < 50 mcg/l)
24 hr Urine arsenic on day 29 was normal, <50 μg/L, and no inorganic arsenic was detected via speciation
DMSA therapy was stopped after results came back normal, with the patient asymptomatic; he developed no signs or symptoms of chronic arsenic posioning, with no alopecia, and no peripheral neuropathy. He remained well after follow-up examination.